U.S. patent application number 10/906879 was filed with the patent office on 2006-09-14 for golf ball.
This patent application is currently assigned to CALLAWAY GOLF COMPANY. Invention is credited to Thomas F. Bergin, Daniel Murphy, Vincent J. Simonds, Thomas A. Veilleux.
Application Number | 20060205536 10/906879 |
Document ID | / |
Family ID | 36971763 |
Filed Date | 2006-09-14 |
United States Patent
Application |
20060205536 |
Kind Code |
A1 |
Bergin; Thomas F. ; et
al. |
September 14, 2006 |
Golf Ball
Abstract
Pinless molding of a cover (24) for a golf ball (20), and an
apparatus and method for manufacturing a golf ball precursor
product (22) for use in pinless molding is disclosed herein.
Preferably the golf ball precursor product (22) comprises a core
(26) and a mantle layer (28). The golf ball precursor product (22)
preferably has a plurality of lobes (30) extending from an
innersphere (27). The plurality of lobes (30) allow the golf ball
precursor product (22) to be centered within a cover mold without
the use of pins for centering.
Inventors: |
Bergin; Thomas F.; (Hoyoke,
MA) ; Murphy; Daniel; (Chicopee, MA) ;
Simonds; Vincent J.; (Brimfield, MA) ; Veilleux;
Thomas A.; (Charlton, MA) |
Correspondence
Address: |
CALLAWAY GOLF C0MPANY
2180 RUTHERFORD ROAD
CARLSBAD
CA
92008-7328
US
|
Assignee: |
CALLAWAY GOLF COMPANY
2180 Rutherford Road
Carlsbad
CA
|
Family ID: |
36971763 |
Appl. No.: |
10/906879 |
Filed: |
March 10, 2005 |
Current U.S.
Class: |
473/377 ;
473/378 |
Current CPC
Class: |
A63B 37/02 20130101;
B29C 45/14065 20130101; A63B 37/0003 20130101; A63B 37/0022
20130101; A63B 37/0013 20130101; A63B 37/008 20130101; B29C
2045/14131 20130101; B29L 2031/54 20130101; A63B 37/0064 20130101;
A63B 37/0075 20130101; B29L 2031/545 20130101; A63B 37/0021
20130101; A63B 37/0019 20130101; A63B 45/00 20130101 |
Class at
Publication: |
473/377 ;
473/378 |
International
Class: |
A63B 37/12 20060101
A63B037/12 |
Claims
1. A method for forming a cover on a golf ball, the method
comprising: positioning a golf ball precursor product within a mold
cavity, the golf ball precursor product having a plurality of lobes
extending outward from an innersphere of the golf ball precursor
product; dispensing a cover material into the mold cavity to form a
cover around the golf ball precursor product; flowing the cover
material around each of the plurality of lobes to provide a cover
with each of the plurality of lobes extending to an unfinished
surface of the golf ball; and applying a coating to the unfinished
surface of the golf ball.
2. The method according to claim 1 wherein the golf ball precursor
product is a core and mantle layer, the plurality of lobes extend
from a surface of the mantle layer.
3. The method according to claim 1 wherein the golf ball precursor
product is a core and the plurality of lobes extend from a surface
of the core.
4. The method according to claim 1 wherein each of the plurality of
lobes has a height ranging from 0.005 inch to 0.100 inch and the
innersphere of golf ball precursor product has a diameter ranging
from 1.45 inches to 1.69 inches.
5. The method according to claim 1 wherein the plurality of lobes
comprises a first lobe positioned on a first hemisphere of the golf
ball precursor product and a second lobe positioned on a second
hemisphere of the golf ball precursor product.
6. The method according to claim 1 wherein the plurality of lobes
comprises a first group of three lobes positioned on a first
hemisphere of the golf ball precursor product and a second group of
three lobes positioned on a second hemisphere of the golf ball
precursor product.
7. The method according to claim 1 wherein dispensing a cover
material into the mold cavity comprises reaction injecting a
material into the mold cavity, the material comprising a reaction
mixture of a polyol reactant and a isocyanate reactant.
8. The method according to claim 1 wherein dispensing a cover
material into the mold cavity comprises injecting a thermoplastic
material into the mold cavity.
9. The method according to claim 1 wherein the coating is a
paint.
10. A golf ball comprising: a golf ball precursor product having a
plurality of lobes, each of the plurality of lobes extending
outward from an innersphere of the golf ball precursor product; a
cover, the cover covering a non-lobe area of the golf ball
precursor product; a coating disposed on the cover and a top of
each of the plurality of lobes.
11. The golf ball according to claim 10 wherein the golf ball
precursor product comprises a core and a mantle, each of the
plurality of lobes extending from a surface of the mantle
layer.
12. The golf ball according to claim 10 wherein the coating
comprises a paint layer and a top coat layer.
13. The golf ball according to claim 10 wherein the coating
comprises a first paint layer, a second paint layer and a top coat
layer.
14. The golf ball according to claim 10 wherein the coating
comprises a top coat layer.
15. The golf ball according to claim 10 wherein the golf ball
precursor product comprises a core, each of the plurality of lobes
extending from a surface of the core.
16. The golf ball according to claim 10 wherein wherein each of the
plurality of lobes has a height ranging from 0.010 inch to 0.100
inch and the innersphere of golf ball precursor product has a
diameter ranging from 1.45 inches to 1.69 inches.
17. The golf ball according to claim 10 wherein the plurality of
lobes comprises a first lobe positioned on a first hemisphere of
the golf ball precursor product and a second lobe positioned on a
second hemisphere of the golf ball precursor product.
18. The golf ball according to claim 10 wherein the plurality of
lobes comprises a first group of three lobes positioned on a first
hemisphere of the golf ball precursor product and a second group of
three lobes positioned on a second hemisphere of the golf ball
precursor product.
19. The golf ball according to claim 10 wherein the plurality of
lobes cover 5% to 25% of the surface area of the innersphere of the
golf ball precursor product.
20. An apparatus for forming a golf ball precursor product with a
plurality of lobes, the apparatus comprising: a first mold half
having a hemispheric surface comprising a smooth portion and a
plurality of deep depressions; a second mold half having a
hemispheric surface comprising a smooth portion and a plurality of
deep depressions; wherein the depth of each of the plurality of
deep depressions of the first mold half and the second mold half
ranges from 0.010 inch to 0.100 inch.
21. The apparatus according to claim 20 wherein the plurality of
deep depressions of the first mold half comprise three deep
depressions positioned equidistant from each other and the
plurality of deep depressions of the second mold half comprise
three deep depressions positioned equidistant from each other.
22. The apparatus according to claim 21 wherein each of the
plurality of deep depressions of the first mold half is positioned
within an a first latitudinal region of the hemispherical surface
of the first mold half, the first latitudinal region ranging from
10 degrees latitude from an edge of the hemispherical surface to 60
degrees latitude from the edge of the hemispherical surface, and
each of the plurality of deep depressions of the second mold half
is positioned within an a first latitudinal region of the
hemispherical surface of the second mold half, the first
latitudinal region ranging from 10 degrees latitude from an edge of
the hemispherical surface to 60 degrees latitude from the edge of
the hemispherical surface.
23. The apparatus according to claim 20 wherein each of the
plurality of deep depressions of the first mold half has a
triangular cross-section, and each of the plurality of deep
depressions of the second mold half has a triangular
cross-section.
24. The apparatus according to claim 1 further comprising a first
plurality of retractable pins that retractably extend through a
first plurality of apertures about a pole of the hemispherical
surface of the first mold half, and a second plurality of
retractable pins that retractably extend through a second plurality
of apertures about a pole of the hemispherical surface of the
second mold half.
25. A method for forming a golf ball precursor product with a
plurality of lobes, the method comprising: placing a spherical core
or pre-core slug within a cavity of a mold assembly, the cavity
defined by a hemispheric surface of the first mold half and a
hemispheric surface of a second mold half, the hemispheric surface
of the first mold half comprising a smooth portion and a plurality
of deep depressions and the hemispheric surface of the second mold
half comprising a smooth portion and a plurality of deep
depressions; and forming a golf ball precursor product with a
plurality of lobes from the spherical core or pre-core slug.
26. The method according to claim 25 wherein a spherical core is
placed within the cavity and forming the golf ball precursor
product with a plurality of lobes comprises injecting a
thermoplastic material into the cavity to form a mantle layer with
a plurality of lobes extending from a surface of the mantle layer,
each of the plurality of lobes formed from thermoplastic material
flowing into a deep depression.
27. The method according to claim 25 wherein a pre-core slug is
placed within the cavity and forming the golf ball precursor
product with a plurality of lobes comprises compressing molding the
pre-core slug within the cavity to form a core with a plurality of
lobes extending from a surface of the core, each of the plurality
of lobes formed from material of the pre-core slug flowing into a
deep depression.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a golf ball. More
specifically, the present invention relates to a golf ball, a
method of forming a golf ball, and an apparatus and method for
forming a golf ball precursor product.
[0003] 2. Description of the Related Art
[0004] Golf balls are typically made by molding a core of
elastomeric or polymeric material into a spheroid shape. A cover is
then molded around the core. Sometimes, before the cover is molded
about the core, an intermediate layer is molded about the core and
the cover is then molded around the intermediate layer. The molding
processes used for the cover and the intermediate layer are similar
and usually involve either compression molding or injection
molding.
[0005] In compression molding, the golf ball core is inserted into
a central area of a two piece die and pre-sized sections of cover
material are placed in each half of the die, which then clamps
shut. The application of heat and pressure molds the cover material
about the core.
[0006] Blends of polymeric materials have been used for modern golf
ball covers because certain grades and combinations have offered
certain levels of hardness to resist damage when the ball is hit
with a club and elasticity to allow responsiveness to the hit. Some
of these materials facilitate processing by compression molding,
yet disadvantages have arisen. These disadvantages include the
presence of seams in the cover, which occur where the pre-sized
sections of cover material were joined, and long process cycle
times which are required to heat the cover material and complete
the molding process.
[0007] Injection molding of golf ball covers arose as a processing
technique to overcome some of the disadvantages of compression
molding. The process involves inserting a golf ball core into a
die, closing the die and forcing a heated, viscous polymeric
material into the die. The material is then cooled and the golf
ball is removed from the die. Injection molding is well-suited for
thermoplastic materials, but has limited application to some
thermosetting polymers. However, certain types of these
thermosetting polymers often exhibit the hardness and elasticity
desired for a golf ball cover. Some of the most promising
thermosetting materials are reactive, requiring two or more
components to be mixed and rapidly transferred into a die before a
polymerization reaction is complete. As a result, traditional
injection molding techniques do not provide proper processing when
applied to these materials.
[0008] Reaction injection molding is a processing technique used
specifically for certain reactive thermosetting plastics. As
mentioned above, by "reactive" it is meant that the polymer is
formed from two or more components that react. Generally, the
components, prior to reacting, exhibit relatively low viscosities.
The low viscosities of the components allow the use of lower
temperatures and pressures than those utilized in traditional
injection molding. In reaction injection molding, the two or more
components are combined and reacted to produce the final
polymerized material. Mixing of these separate components is
critical, a distinct difference from traditional injection
molding.
[0009] The process of reaction injection molding a golf ball cover
involves placing a golf ball core into a die, closing the die,
injecting the reactive components into a mixing chamber where they
combine, and transferring the combined material into the die. The
mixing begins the polymerization reaction, which is typically
completed upon cooling of the cover material.
[0010] The present invention provides an improved golf ball and a
new mold configuration for injection molding a golf ball cover or
inner layer which promotes self-centering of the core or core and
core or mantle layer(s), resulting in reduction of cosmetic defects
and cover damage, enhanced properties and more efficient molding
processes.
[0011] For certain applications it is desirable to produce a golf
ball having a very thin cover layer. However, due to equipment
limitations, it is often very difficult to mold a thin cover.
Accordingly, it would be beneficial to provide an apparatus and
technique for producing a relatively thin cover layer.
[0012] Moreover, retractable pins have been utilized to hold, or
center, the core or core and mantle and/or cover layer(s) in place
within a mold while molding an inner or outer cover layer thereon.
In such processes, the core or mantled ball is supported in the
mold using retractable pins extending from the inner surface of the
mold to the outer surface of the core or mantled ball. The pins in
essence support the core or mantled ball while the cover layer is
injected into the mold. Subsequently, the pins are retracted as the
cover material fills the void between the core or mantle and the
inner surface of the mold.
[0013] However, notwithstanding, the benefits produced through the
use of the retractable pins, the pins sometimes produce centering
difficulties and cosmetic problems (i.e. pin flash, pin marks,
etc.) during retraction, which in turn require additional handling
to produce a golf ball suitable for use and sale. Additionally, the
lower the viscosity of the mantle and/or cover materials, the
greater the tendency for the retractable pins to stick due to
material accumulation, making it necessary to shut down and clean
the molds routinely. Accordingly, it would be desirable to provide
golf ball and an apparatus forming a cover layer on a golf ball
without the use of retractable pins.
BRIEF SUMMARY OF THE INVENTION
[0014] The present invention provides a solution to the need for
pinless molding of a cover. The present invention provides a golf
ball precursor product with a plurality of lobes extending from an
innersphere. The lobes allow for the centering of the golf ball
precursor product within a mold for forming a cover.
[0015] One aspect of the present invention is a method for forming
a cover on a golf ball. The method begins with positioning a golf
ball precursor product within a mold cavity, with the golf ball
precursor product having a plurality of lobes extending outward
from an innersphere of the golf ball precursor product. Next, a
cover material is dispensed into the mold cavity to form a cover
around the golf ball precursor product. Next, the cover material is
flowed around each of the plurality of lobes to provide a cover
with each of the plurality of lobes extending to an unfinished
surface of the golf ball. Next, a coating is applied to the
unfinished surface of the golf ball.
[0016] Another aspect of the present invention is a golf ball
having a golf ball precursor product, a cover and a coating. The
golf ball precursor product has a plurality of lobes, with each of
the plurality of lobes extending outward from an innersphere of the
golf ball precursor product. The cover covers a non-lobe area of
the golf ball precursor product. The coating is disposed on the
cover and a top of each of the plurality of lobes.
[0017] Yet another aspect of the present invention is an apparatus
for forming a golf ball precursor product with a plurality of
lobes. The apparatus includes a first mold half having a
hemispheric surface comprising a smooth portion and a plurality of
deep depressions and a second mold half having a hemispheric
surface comprising a smooth portion and a plurality of deep
depressions. The depth of each of the plurality of deep depressions
of the first mold half and the second mold half ranges from 0.010
inch to 0.100 inch.
[0018] Yet another aspect of the present invention is a method for
forming a golf ball precursor product with a plurality of lobes.
The method begins with placing a spherical core or pre-core slug
within a cavity of a mold assembly. The cavity is defined by a
hemispheric surface of the first mold half and a hemispheric
surface of a second mold half. The hemispheric surface of the first
mold half includes a smooth portion and a plurality of deep
depressions and the hemispheric surface of the second mold half
includes a smooth portion and a plurality of deep depressions.
Next, a golf ball precursor product is formed with a plurality of
lobes from the spherical core or pre-core slug.
[0019] Having briefly described the present invention, the above
and further objects, features and advantages thereof will be
recognized by those skilled in the pertinent art from the following
detailed description of the invention when taken in conjunction
with the accompanying drawings.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0020] FIG. 1 is a cross-sectional view of a three-piece golf
ball.
[0021] FIG. 2 is a partial cut-away view of a three-piece golf
ball.
[0022] FIG. 3 is a cross-sectional view of a two-piece golf
ball.
[0023] FIG. 4 is a partial cut-away view of a two-piece golf
ball.
[0024] FIG. 5 is equatorial view of a golf ball.
[0025] FIG. 6 is a cross-sectional view along line 6-6 of FIG.
5.
[0026] FIG. 7 is an isolated cross-sectional view of a lobe area of
a golf ball having a top coat.
[0027] FIG. 8 is an isolated cross-sectional view of a lobe area of
a golf ball having a top coat and a paint layer.
[0028] FIG. 9 is an isolated cross-sectional view of a lobe area of
a golf ball having a top coat and two paint layers.
[0029] FIG. 10 is a cross-sectional view of a mold utilized in
forming a golf ball precursor product.
[0030] FIG. 11 is a cross-sectional view of a mold utilized in
forming a golf ball precursor product with a pre-core slug
therein.
[0031] FIG. 12 is a cross-sectional view of a mold utilized in
forming a golf ball precursor product with a core therein.
[0032] FIG. 13 is a top view of a mold half utilized in forming a
golf ball precursor product.
[0033] FIG. 14 is a cross-sectional view along line 14-14 of the
mold half of FIG. 13.
[0034] FIG. 15 is a view of a mold assembly utilized in forming a
cover.
[0035] FIG. 16 is an isolated view of a portion of the mold
assembly of FIG. 1 5 with a golf ball.
[0036] FIG. 17 is a cross-sectional view of a golf ball precursor
product within a cavity of a mold assembly utilized in forming a
cover.
[0037] FIG. 18 is a cross-sectional view of a golf ball.
DETAILED DESCRIPTION OF THE INVENTION
[0038] As shown in FIGS. 1-6, a golf ball is generally designated
20. The golf ball 20 includes a golf ball precursor product 22 and
a cover 24. The golf ball precursor product 22 has a plurality of
lobes 30 extending from an innersphere 27 of the golf ball
precursor product 22. The golf ball precursor product 22 is
preferably a core 26 and a mantle layer 28, as shown in FIGS. 1 and
2. Alternatively, the golf ball precursor product 22 is only a core
26, as shown in FIGS. 3 and 4. Still other embodiments may include
multiple mantle layers and a multiple cores including solid, hollow
and liquid-filled cores.
[0039] In a preferred embodiment, the golf ball precursor product
22 has six lobes 30 with three lobes 30 on each hemisphere 38a and
38b of the golf ball precursor product 22. In yet another
embodiment, the golf ball precursor product 22 has twelve lobes 30
with six lobes 30 on each hemisphere 38a and 38b of the golf ball
precursor product 22. In yet another embodiment, the golf ball
precursor product 22 has two lobes 30 with a single lobe 30 on each
hemisphere 38a and 38b of the golf ball precursor product 22. Those
skilled in the pertinent art will recognize that the number of
lobes 30 may vary form the above-mentioned embodiments without
departing from the scope and spirit of the present invention.
[0040] The height, "HL", of each of the lobes 30 preferably ranges
from about 0.001 inch to about 0.090 inch, more preferably from
about 0.001 inch to about 0.030 inch, and more preferably from
about 0.001 inch to about 0.015 inch. Most preferably a total
height of at least about 0.001 inch is desired for each lobe 30.
More preferably, each of the plurality of lobes 30 has a height
that is equal or approximately equal to the thickness of the cover
24. All of the plurality of lobes 30 preferably have the same
shape. Alternatively, the shape of each of the plurality of lobes
30 may vary. Preferably each of the plurality of lobes 30 has a
width, "W.sub.L", as measured across a lobe 30 and shown in FIG. 6,
ranging from about 0.05 inch to about 0.50 inch, more preferably
from about 0.10 inch to about 0.30 inch, and even more preferably
from about 0.14 inch to about 0.35 inch.
[0041] In a preferred embodiment, a top surface 36 of each of the
plurality of lobes 30 extends to an unfinished surface 34 of the
golf ball 20, as shown in FIG. 5. As explained in greater detail
below in reference to manufacturing the golf ball 20, the plurality
of lobes 30 preferably allow for "pinless" forming of the cover 24
over the non-lobe area 32 of the surface of the golf ball precursor
product 22. More preferably, the plurality of lobes 30 allow for
"pinless" injection molding, including reaction injection molding,
of the cover 24 over the non-lobe area 32 of the surface of the
golf ball precursor product 22. The plurality of lobes 30
preferably center the innersphere 27 of the golf ball precursor
product 22 during the cover molding process to ensure core to cover
concentricity.
[0042] As shown in FIGS. 7-9, the golf ball 20 is finished with a
coating 40, which covers the top surface 36 of each of the
plurality of lobes 30. In this manner, the top surface 36 of the
each of the plurality of lobes 30 is "hidden" so that the golf ball
20 preferably has a uniform surface appearance. In one embodiment
shown in FIG. 7, the coating 40 is a single top coat layer 42. In a
second embodiment shown in FIG. 8, the coating 40 is a first paint
layer 44 (preferably white paint) and a top coat layer 42. In a
third embodiment shown in FIG. 9, the coating 40 is a first paint
layer 44, a second paint layer 46 and a top coat layer 42. Those
skilled in the pertinent art will recognize that the coating may
vary in layers without departing from the scope and spirit of the
present invention.
[0043] FIGS. 10-14 illustrate an apparatus for forming the golf
ball precursor product 22 with a plurality of lobes 30. A mold
assembly is generally designated 50. The mold assembly 50 is
preferably utilized in injection molding the mantle layer 28 on the
core 26. Alternatively, the mold assembly 50 is utilized in
injection molding the core 26. In yet another alternative
embodiment, the mold assembly 50 is utilized in compression molding
a pre-core slug 23, as shown in FIG. 11, into a core 26 with a
plurality of lobes 30.
[0044] In a preferred embodiment shown in FIG. 12, the mold
assembly 50 includes a first mold 54a and a second mold half 54b. A
cavity 52 is defined by a hemispheric surface 56a and 56b of each
of the mold halves 54a and 54b. Each hemispheric surface 56a and
56b has a smooth portion 58 and a plurality of deep depressions 60.
The plurality of deep depressions 60 forms the plurality of lobes
30. In a preferred embodiment, the mold assembly 50 has six
depressions 60 with three depressions 60 in each hemispheric
surface 56a and 56b. In yet another embodiment, the mold assembly
50 has twelve depressions 60 with six depressions 60 on each
hemispheric surface 56a and 56b. In yet another embodiment, the
mold assembly 50 has two depressions 60 with a single depression 60
on each hemispheric surface 56a and 56b. Those skilled in the
pertinent art will recognize that the number of depressions 60 may
vary form the above-mentioned embodiments without departing from
the scope and spirit of the present invention.
[0045] A plurality of retractable pins 66 extend from a
corresponding aperture 68 in each of the mold halves 54a and 54b.
The retractable pins 66 preferably hold a core 26 within the cavity
52 during injection molding of the mantle layer 28 thereon. Use of
such retractable pins is well-known in the relevant art. The
retractable pins 66 are typically located near a pole 62 of a
hemispheric surface 56a or 56b. Each of the plurality of deep
depressions 60 in each of the hemispheric surfaces 56a and 56b is
preferably located equidistant from each other within a first
latitudinal region which preferably ranges from 1 0 degrees to 60
degrees longitude from an edge 64 of each respective hemispheric
surface 56a or 56b.
[0046] The depth of each depression 60 preferably ranges from about
0.001 inch to about 0.100 inch, more preferably from about 0.001
inch to about 0.030 inch, and more preferably from about 0.001 inch
to about 0.015 inch. A most preferred depth of each depression 60
is 0.010 inch. Those skilled in the pertinent art will recognize
that the depth of each depression 60 may vary from each other
depression 60 without departing from the scope and spirit of the
present invention.
[0047] The golf ball precursor product 22 with a plurality of lobes
30 is preferably utilized in reaction injection molding ("RIM") a
cover 24. The plurality of lobes 30 allow for the golf ball
precursor product 22 to be centered during the formation of the
cover 24 without the use of centering or retractable pins. Such
pinless centering is important with RIM since the material
solidifies quickly relative to other cover materials and can cause
the pins to become jammed or blocked.
[0048] As shown in FIGS. 15-17, the preferred embodiment RIM
molding assembly 1 20 provides mixing as a result of its unique
design and configuration. An injection machine, as known in the
art, is connected to the RIM molding assembly 120 which comprises
an upper half 122A and a lower half 122B. As will be appreciated,
the upper and lower halves 122A and 122B are preferably formed from
a metal or suitable material. A mixing chamber may, as known in the
art, precede the molding assembly 120 if desired. A golf ball
precursor product 22 is positioned within a substantially spherical
cavity formed from two hemispherical cavities 124A and 124B defined
in opposing faces of the upper half and lower half 122A and 122B,
respectively, of the molding assembly 120. As will be appreciated,
when the upper and lower halves 122A and 122B are closed, and the
cavities 124A and 124B are aligned with each other, the resulting
cavity has a substantially spherical configuration. Each of the
hemispherical cavities 124A and 124B defines a plurality of raised
regions that, upon molding a cover layer therein, will result in an
aerodynamic pattern on the cover 24. Such aerodynamic pattern may
be a traditional dimple pattern or a pattern such as disclosed in
U.S. Pat. No. 6,290,615 for a Golf Ball Having A Tubular Lattice
Pattern.
[0049] Each upper and lower half 122A and 122B of the preferred
embodiment molding assembly 120 defines an adapter portion 126A and
126B to enable the molding assembly 120 to connect to other process
equipment as mentioned above and leads to a material inlet channel
128A and 128B. As will be understood, upon closing the upper and
lower halves 122A and 122B of the molding assembly 120, the
separate halves of adapter portion 126A and 126B are aligned with
each other and create a material flow inlet within the molding
assembly 120. Each upper and lower half 122A and 122B of the
assembly 120 further defines flow channels 128A and 128B, 130A and
130B and 132A and 132B which create a comprehensive flow channel
within the molding assembly 120 when the upper and lower halves
122A and 122B are closed. Specifically, the material flow inlet
channel portion 128A, 128B receives the constituent materials from
the adapter portion 126A and 126B and directs those materials to a
turbulence-promoting portion of the channel 130A, 130B which is
configured to form at least one fan gate. The upper and lower mold
halves 122A and 122B include complimentary turbulence-promoting
peanut after-mixer channel portions 130A and 130B, respectively. It
will be appreciated that upon closing the upper and lower halves
122A and 122B of the molding assembly 120, the channel portion 130A
and 130B defines a region of the flow channel that is generally
nonlinear and includes a plurality of bends and at least one
branching intersection generally referred to herein as an
after-mixer gate. Each after-mixer channel portion 130A, 130B is
designed to direct material flow along an angular or tortuous path.
As will be described in more detail below, when material reaches a
terminus of angular flow in one plane of the flow channel in one
half, the material flows in a transverse manner to a corresponding
after-mixer channel portion in the opposing half. Thus, when the
constituent materials arrive at the after-mixer defined by the
channel portion 130A and 130B, turbulent flow is promoted, forcing
the materials to continue to mix within the molding assembly 120.
This mixing within the molding assembly 120 provides for improved
overall mixing of the constituent materials, thereby resulting in a
more uniform and homogeneous composition for the cover 24.
[0050] The material inlet channel 128A and 128B allows entry of the
constituents which are subsequently directed through the
mix-promoting channel portion 130A and 130B, which forms the
after-mixer, then through the connecting channel portion 132A and
132B and to the fan gate portion 134A and 134B which leads into the
cavity 124A and 124B. The final channel portion 134A and 134B may
be defined in several forms extending to the cavity 124A and 124B,
including corresponding or complimentary paths which may be closed
(134A) or open (134B) and of straight, curved or angular (134A,
134B) shape.
[0051] It has been discovered that because of the reduced process
pressure involved in RIM, fewer supporting structures (the lobes
30) are necessary in the molding assembly 120 to centrally position
the golf ball precursor product 22 in the central cavity 124A and
124B. Preferably, only three lobes 30 or less may be necessary per
mold half. For some embodiments, it is preferred to utilize six
lobes 30 per mold half. The use of lobes 30 reduces the cost of the
tooling and reduces problems such as defacement and surface
imperfections caused by retractable pins. A channel leading from
the cavity 124A and 124B may be provided as either a cavity venting
channel or an overflow channel or dump well as known in the art. A
dump well 131a and 131B is provided in the corresponding molds. A
dump well vent 133A, 133B provides communication between the dump
well and mold exterior. A venting channel 129A, 129B is defined in
the molds and provides communication between the central cavity
124A, 124B and the dump well 131A, 131B. It will be appreciated
that when the upper and lower halves 122A and 122B are closed, the
respective portions of the channel align with one another to form
the venting or overflow channel.
[0052] In a preferred embodiment, the cover 24 is composed of a RIM
polyurethane material. In an alternative embodiment, the golf ball
20 is constructed with a cover 24 composed of a polyurethane
material as set forth in U.S. Pat. No. 6,117,024, for a Golf Ball
With A Polyurethane Cover, which pertinent parts are hereby
incorporated by reference. The golf ball 20 preferably has a
coefficient of restitution at 143 feet per second greater than
0.7964, and an USGA initial velocity less than 255.0 feet per
second. The golf ball 20 more preferably has a COR of approximately
0.8152 at 143 feet per second, and an initial velocity between 250
feet per second to 255 feet per second under USGA initial velocity
conditions. A more thorough description of a high COR golf ball is
disclosed in U.S. Pat. No. 6,443,858, which pertinent parts are
hereby incorporated by reference.
[0053] Additionally, the core 26 of the golf ball 20 may be solid,
hollow, or filled with a fluid, such as a gas or liquid, or have a
metal mantle. The cover 24 of the golf ball 20 may be any suitable
material. A preferred cover for a three-piece golf ball is composed
of a thermoset polyurethane material. Alternatively, the cover 24
is composed of a thermoplastic polyurethane, ionomer blend, ionomer
rubber blend, ionomer and thermoplastic polyurethane blend, or like
materials. Those skilled in the pertinent art will recognize that
other cover materials may be utilized without departing from the
scope and spirit of the present invention. The golf ball 20 may
have a finish of one or two basecoats and/or one or two top
coats.
[0054] In an alternative embodiment of a golf ball 20, the mantle
layer 28 or cover layer 24 is comprised of a high acid (i.e.
greater than 16 weight percent acid) ionomer resin or high acid
ionomer blend. More preferably, the mantle layer 28 is comprised of
a blend of two or more high acid (i.e. greater than 16 weight
percent acid) ionomer resins neutralized to various extents by
different metal cations.
[0055] In an alternative embodiment of a golf ball 20, the mantle
layer 28 or cover layer 24 is comprised of a low acid (i.e. 16
weight percent acid or less) ionomer resin or low acid ionomer
blend. Preferably, the mantle layer 28 is comprised of a blend of
two or more low acid (i.e. 16 weight percent acid or less) ionomer
resins neutralized to various extents by different metal cations.
The mantle layer 28 compositions of the embodiments described
herein may include the high acid ionomers such as those developed
by E. I. DuPont de Nemours & Company under the SURLYN brand,
and by Exxon Corporation under the ESCOR or IOTEK brands, or blends
thereof. Examples of compositions which may be used as the mantle
layer 28 herein are set forth in detail in U.S. Pat. No. 5,688,869,
which is incorporated herein by reference. Of course, the mantle
layer 28 high acid ionomer compositions are not limited in any way
to those compositions set forth in said patent. Those compositions
are incorporated herein by way of examples only.
[0056] The high acid ionomers which may be suitable for use in
formulating the mantle layer 28 compositions are ionic copolymers
which are the metal (such as sodium, zinc, magnesium, etc.) salts
of the reaction product of an olefin having from about 2 to 8
carbon atoms and an unsaturated monocarboxylic acid having from
about 3 to 8 carbon atoms. Preferably, the ionomeric resins are
copolymers of ethylene and either acrylic or methacrylic acid. In
some circumstances, an additional comonomer such as an acrylate
ester (for example, iso- or n-butylacrylate, etc.) can also be
included to produce a softer terpolymer. The carboxylic acid groups
of the copolymer are partially neutralized (for example,
approximately 10-100%, preferably 30-70%) by the metal ions. Each
of the high acid ionomer resins which may be included in the inner
layer cover compositions of the invention contains greater than 16%
by weight of a carboxylic acid, preferably from about 17% to about
25% by weight of a carboxylic acid, more preferably from about
18.5% to about 21.5% by weight of a carboxylic acid. Examples of
the high acid methacrylic acid based ionomers found suitable for
use in accordance with this invention include, but are not limited
to, SURLYN 8220 and 8240 (both formerly known as forms of SURLYN
AD-8422), SURLYN 9220 (zinc cation), SURLYN SEP-503-1 (zinc
cation), and SURLYN SEP-503-2 (magnesium cation). According to
DuPont, all of these ionomers contain from about 18.5 to about
21.5% by weight methacrylic acid. Examples of the high acid acrylic
acid based ionomers suitable for use in the present invention also
include, but are not limited to, the high acid ethylene acrylic
acid ionomers produced by Exxon such as Ex 1001, 1002, 959, 960,
989, 990, 1003, 1004, 993, and 994. In this regard, ESCOR or IOTEK
959 is a sodium ion neutralized ethylene-acrylic neutralized
ethylene-acrylic acid copolymer. According to Exxon, IOTEKS 959 and
960 contain from about 19.0 to about 21.0% by weight acrylic acid
with approximately 30 to about 70 percent of the acid groups
neutralized with sodium and zinc ions, respectively.
[0057] Furthermore, as a result of the previous development by the
assignee of this application of a number of high acid ionomers
neutralized to various extents by several different types of metal
cations, such as by manganese, lithium, potassium, calcium and
nickel cations, several high acid ionomers and/or high acid ionomer
blends besides sodium, zinc and magnesium high acid ionomers or
ionomer blends are also available for golf ball cover production.
It has been found that these additional cation neutralized high
acid ionomer blends produce mantle layer 28 compositions exhibiting
enhanced hardness and resilience due to synergies which occur
during processing. Consequently, these metal cation neutralized
high acid ionomer resins can be blended to produce substantially
higher C.O.R.'s than those produced by the low acid ionomer mantle
layer 28 compositions presently commercially available.
[0058] More particularly, several metal cation neutralized high
acid ionomer resins have been produced by the assignee of this
invention by neutralizing, to various extents, high acid copolymers
of an alpha-olefin and an alpha, beta-unsaturated carboxylic acid
with a wide variety of different metal cation salts. This discovery
is the subject matter of U.S. Pat. No. 5,688,869, incorporated
herein by reference. It has been found that numerous metal cation
neutralized high acid ionomer resins can be obtained by reacting a
high acid copolymer (i.e. a copolymer containing greater than 16%
by weight acid, preferably from about 17 to about 25 weight percent
acid, and more preferably about 20 weight percent acid), with a
metal cation salt capable of ionizing or neutralizing the copolymer
to the extent desired (for example, from about 10% to 90%).
[0059] The base copolymer is made up of greater than 16% by weight
of an alpha, beta-unsaturated carboxylic acid and an alpha-olefin.
Optionally, a softening comonomer can be included in the copolymer.
Generally, the alpha-olefin has from 2 to 10 carbon atoms and is
preferably ethylene, and the unsaturated carboxylic acid is a
carboxylic acid having from about 3 to 8 carbons. Examples of such
acids include acrylic acid, methacrylic acid, ethacrylic acid,
chloroacrylic acid, crotonic acid, maleic acid, fumaric acid, and
itaconic acid, with acrylic acid being preferred.
[0060] The softening comonomer that can be optionally included in
the mantle layer 28 of the golf ball of the invention may be
selected from the group consisting of vinyl esters of aliphatic
carboxylic acids wherein the acids have 2 to 10 carbon atoms, vinyl
ethers wherein the alkyl groups contain 1 to 10 carbon atoms, and
alkyl acrylates or methacrylates wherein the alkyl group contains 1
to 10 carbon atoms. Suitable softening comonomers include vinyl
acetate, methyl acrylate, methyl methacrylate, ethyl acrylate,
ethyl methacrylate, butyl acrylate, butyl methacrylate, or the
like.
[0061] Consequently, examples of a number of copolymers suitable
for use to produce the high acid ionomers included in the present
invention include, but are not limited to, high acid embodiments of
an ethylene/acrylic acid copolymer, an ethylene/methacrylic acid
copolymer, an ethylene/itaconic acid copolymer, an ethylene/maleic
acid copolymer, an ethylene/methacrylic acid/vinyl acetate
copolymer, an ethylene/acrylic acid/vinyl alcohol copolymer, etc.
The base copolymer broadly contains greater than 16% by weight
unsaturated carboxylic acid, from about 39 to about 83% by weight
ethylene and from 0 to about 40% by weight of a softening
comonomer. Preferably, the copolymer contains about 20% by weight
unsaturated carboxylic acid and about 80% by weight ethylene. Most
preferably, the copolymer contains about 20% acrylic acid with the
remainder being ethylene.
[0062] The mantle layer 28 compositions may include the low acid
ionomers such as those developed and sold by E. 1. DuPont de
Nemours & Company under the SURLYN and by Exxon Corporation
under the brands ESCOR and IOTEK, ionomers made in-situ, or blends
thereof.
[0063] Another embodiment of the mantle layer 28 comprises a
non-ionomeric thermoplastic material or thermoset material.
Suitable non-ionomeric materials include, but are not limited to,
metallocene catalyzed polyolefins or polyamides, polyamide/ionomer
blends, polyphenylene ether/ionomer blends, etc., which preferably
have a Shore D hardness of at least 60 (or a Shore C hardness of at
least about 90) and a flex modulus of greater than about 30,000
psi, preferably greater than about 50,000 psi, or other hardness
and flex modulus values which are comparable to the properties of
the ionomers described above. Other suitable materials include but
are not limited to, thermoplastic or thermosetting polyurethanes,
thermoplastic block polyesters, for example, a polyester elastomer
such as that marketed by DuPont under the brand HYTREL, or
thermoplastic block polyamides, for example, a polyether amide such
as that marketed by Elf Atochem S. A. under the brand PEBEX, a
blend of two or more non-ionomeric thermoplastic elastomers, or a
blend of one or more ionomers and one or more non-ionomeric
thermoplastic elastomers. These materials can be blended with the
ionomers described above in order to reduce cost relative to the
use of higher quantities of ionomer.
[0064] Additional materials suitable for use in the mantle layer 28
or cover layer 24 of the present invention include polyurethanes.
These are described in more detail below.
[0065] In one embodiment, the cover layer 24 is comprised of a
relatively soft, low flex modulus (about 500 psi to about 50,000
psi, preferably about 1,000 psi to about 25,000 psi, and more
preferably about 5,000 psi to about 20,000 psi) material or blend
of materials. Preferably, the cover layer 24 comprises a
polyurethane, a polyurea, a blend of two or more
polyurethanes/polyureas, or a blend of one or more ionomers or one
or more non-ionomeric thermoplastic materials with a
polyurethane/polyurea, preferably a thermoplastic polyurethane or
reaction injection molded polyurethane/polyurea (described in more
detail below).
[0066] The cover layer 24 preferably has a thickness in the range
of 0.005 inch to about 0.15 inch, more preferably about 0.010 inch
to about 0.050 inch, and most preferably 0.015 inch to 0.025 inch.
In one embodiment, the cover layer 24 has a Shore D hardness of 60
or less (or less than 90 Shore C), and more preferably 55 or less
(or about 80 Shore C or less). In another preferred embodiment, the
cover layer 24 is comparatively harder than the mantle layer
28.
[0067] In one preferred embodiment, the cover layer 24 comprises a
polyurethane, a polyurea or a blend of polyurethanes/polyureas.
Polyurethanes are polymers which are used to form a broad range of
products. They are generally formed by mixing two primary
ingredients during processing. For the most commonly used
polyurethanes, the two primary ingredients are a polyisocyanate
(for example, 4,4'-diphenylmethane diisocyanate monomer ("MDI") and
toluene diisocyanate ("TDI") and their derivatives) and a polyol
(for example, a polyester polyol or a polyether polyol).
[0068] A wide range of combinations of polyisocyanates and polyols,
as well as other ingredients, are available. Furthermore, the
end-use properties of polyurethanes can be controlled by the type
of polyurethane utilized, such as whether the material is thermoset
(cross linked molecular structure not flowable with heat) or
thermoplastic (linear molecular structure flowable with heat).
[0069] Cross linking occurs between the isocyanate groups (----NCO)
and the polyol's hydroxyl end-groups (----OH). Cross linking will
also occur between the NH.sub.2 group of the amines and the NCO
groups of the isocyanates, forming a polyurea. Additionally, the
end-use characteristics of polyurethanes can also be controlled by
different types of reactive chemicals and processing parameters.
For example, catalysts are utilized to control polymerization
rates. Depending upon the processing method, reaction rates can be
very quick (as in the case for some reaction injection molding
systems ("RIM")) or may be on the order of several hours or longer
(as in several coating systems such as a cast system).
Consequently, a great variety of polyurethanes are suitable for
different end-uses.
[0070] Polyurethanes are typically classified as thermosetting or
thermoplastic. A polyurethane becomes irreversibly "set" when a
polyurethane prepolymer is cross linked with a polyfunctional
curing agent, such as a polyamine or a polyol. The prepolymer
typically is made from polyether or polyester. A prepolymer is
typically an isocyanate terminated polymer that is produced by
reacting an isocyanate with a moiety that has active hydrogen
groups, such as a polyester and/or polyether polyol. The reactive
moiety is a hydroxyl group. Diisocyanate polyethers are preferred
because of their water resistance.
[0071] The physical properties of thermoset polyurethanes are
controlled substantially by the degree of cross linking and by the
hard and soft segment content. Tightly cross linked polyurethanes
are fairly rigid and strong. A lower amount of cross linking
results in materials that are flexible and resilient. Thermoplastic
polyurethanes have some cross linking, but primarily by physical
means, such as hydrogen bonding. The crosslinking bonds can be
reversibly broken by increasing temperature, such as during molding
or extrusion. In this regard, thermoplastic polyurethanes can be
injection molded, and extruded as sheet and blow film. They can be
used up to about 400 degrees Fahrenheit, and are available in a
wide range of hardnesses.
[0072] Polyurethane materials suitable for the present invention
may be formed by the reaction of a polyisocyanate, a polyol, and
optionally one or more chain extenders. The polyol component
includes any suitable polyether- or polyester polyol. Additionally,
in an alternative embodiment, the polyol component is polybutadiene
diol. The chain extenders include, but are not limited to, diols,
triols and amine extenders. Any suitable polyisocyanate may be used
to form a polyurethane according to the present invention. The
polyisocyanate is preferably selected from the group of
diisocyanates including, but not limited to, 4,4'-diphenylmethane
diisocyanate ("MDI"); 2,4-toluene diisocyanate ("TDI"); m-xylylene
diisocyanate ("XDI"); methylene bis-(4-cyclohexyl isocyanate)
("HMDI"); hexamethylene diisocyanate ("HDI");
naphthalene-1,5,-diisocyanate ("NDI"); 3,3'-dimethyl-4,4'-biphenyl
diisocyanate ("TODI"); 1,4-diisocyanate benzene ("PPDI");
phenylene-1,4-diisocyanate; and 2,2,4- or 2,4,4-trimethyl
hexamethylene diisocyanate ("TMDI").
[0073] Other less preferred diisocyanates include, but are not
limited to, isophorone diisocyanate ("IPDI"); 1,4-cyclohexyl
diisocyanate ("CHDI"); diphenylether-4,4'-diisocyanate;
p,p'-diphenyl diisocyanate; lysine diisocyanate ("LDI"); 1,3-bis
(isocyanato methyl) cyclohexane; and polymethylene polyphenyl
isocyanate ("PMDI").
[0074] One additional polyurethane component which can be used in
the present invention incorporates TMXDI ("META") aliphatic
isocyanate (Cytec Industries, West Paterson, N.J.). Polyurethanes
based on meta-tetramethylxylylene diisocyanate (TMXDI) can provide
improved gloss retention UV light stability, thermal stability, and
hydrolytic stability. Additionally, TMXDI ("META") aliphatic
isocyanate has demonstrated favorable toxicological properties.
Furthermore, because it has a low viscosity, it is usable with a
wider range of diols (to polyurethane) and diamines (to polyureas).
If TMXDI is used, it typically, but not necessarily, is added as a
direct replacement for some or all of the other aliphatic
isocyanates in accordance with the suggestions of the supplier.
Because of slow reactivity of TMXDI, it may be useful or necessary
to use catalysts to have practical demolding times. Hardness,
tensile strength and elongation can be adjusted by adding further
materials in accordance with the supplier's instructions.
[0075] The cover layer 24 preferably comprises a polyurethane with
a Shore D hardness (plaque) of from about 10 to about 55 (Shore C
of about 15 to about 75), more preferably from about 25 to about 55
(Shore C of about 40 to about 75), and most preferably from about
30 to about 55 (Shore C of about 45 to about 75) for a soft cover
layer 24 and from about 20 to about 90, preferably about 30 to
about 80, and more preferably about 40 to about 70 for a hard cover
layer 14.
[0076] The polyurethane preferably has a flex modulus from about 1
to about 310 Kpsi, more preferably from about 3 to about 100 Kpsi,
and most preferably from about 3 to about 40 Kpsi for a soft cover
layer 14 and 40 to 90 Kpsi for a hard cover layer 24.
[0077] Non-limiting examples of a polyurethane suitable for use in
mantle layer 28 include a thermoplastic polyester polyurethane such
as Bayer Corporation's TEXIN polyester polyurethane (such as TEXIN
DP7-1097 and TEXIN 285 grades) and a polyester polyurethane such as
B. F. Goodrich Company's ESTANE polyester polyurethane (such as
ESTANE X-4517 grade). The thermoplastic polyurethane material may
be blended with a soft ionomer or other non-ionomer. For example,
polyamides blend well with soft ionomer.
[0078] Other soft, relatively low modulus non-ionomeric
thermoplastic or thermoset polyurethanes may also be utilized, as
long as the non-ionomeric materials produce the playability and
durability characteristics desired without adversely affecting the
enhanced travel distance characteristic produced by the high acid
ionomer resin composition. These include, but are not limited to
thermoplastic polyurethanes such as the PELLETHANE thermoplastic
polyurethanes from Dow Chemical Co.; and non-ionomeric thermoset
polyurethanes including but not limited to those disclosed in U.S.
Pat. No. 5,334,673 incorporated herein by reference.
[0079] Typically, there are two classes of thermoplastic
polyurethane materials: aliphatic polyurethanes and aromatic
polyurethanes. The aliphatic materials are produced from a polyol
or polyols and aliphatic isocyanates, such as H.sub.12MDI or HDI,
and the aromatic materials are produced from a polyol or polyols
and aromatic isocyanates, such as MDI or TDI. The thermoplastic
polyurethanes may also be produced from a blend of both aliphatic
and aromatic materials, such as a blend of HDI and TDI with a
polyol or polyols.
[0080] Generally, the aliphatic thermoplastic polyurethanes are
lightfast, meaning that they do not yellow appreciably upon
exposure to ultraviolet light. Conversely, aromatic thermoplastic
polyurethanes tend to yellow upon exposure to ultraviolet light.
One method of stopping the yellowing of the aromatic materials is
to paint the outer surface of the finished ball with a coating
containing a pigment, such as titanium dioxide, so that the
ultraviolet light is prevented from reaching the surface of the
ball. Another method is to add UV absorbers, optical brighteners
and stabilizers to the clear coating(s) on the outer cover, as well
as to the thermoplastic polyurethane material itself. By adding UV
absorbers and stabilizers to the thermoplastic polyurethane and the
coating(s), aromatic polyurethanes can be effectively used in the
outer cover layer of golf balls. This is advantageous because
aromatic polyurethanes typically have better scuff resistance
characteristics than aliphatic polyurethanes, and the aromatic
polyurethanes typically cost less than the aliphatic
polyurethanes.
[0081] Other suitable polyurethane materials for use in the present
invention golf balls include reaction injection molded ("RIM")
polyurethanes. RIM is a process by which highly reactive liquids
are injected into a mold, mixed usually by impingement and/or
mechanical mixing in an in-line device such as a "peanut mixer,"
where they polymerize primarily in the mold to form a coherent,
one-piece molded article. The RIM process usually involves a rapid
reaction between one or more reactive components such as a
polyether polyol or polyester polyol, polyamine, or other material
with an active hydrogen, and one or more isocyanate-containing
constituents, often in the presence of a catalyst. The constituents
are stored in separate tanks prior to molding and may be first
mixed in a mix head upstream of a mold and then injected into the
mold. The liquid streams are metered in the desired weight to
weight ratio and fed into an impingement mix head, with mixing
occurring under high pressure, for example, 1,500 to 3,000 psi. The
liquid streams impinge upon each other in the mixing chamber of the
mix head and the mixture is injected into the mold. One of the
liquid streams typically contains a catalyst for the reaction. The
constituents react rapidly after mixing to gel and form
polyurethane polymers. Polyureas, epoxies, and various unsaturated
polyesters also can be molded by RIM. Further descriptions of
suitable RIM systems is disclosed in U.S. Pat. No. 6,663,508, which
pertinent parts are hereby incorporated by reference.
[0082] Non-limiting examples of suitable RIM systems for use in the
present invention are BAYFLEX elastomeric polyurethane RIM systems,
BAYDUR GS solid polyurethane RIM systems, PRISM solid polyurethane
RIM systems, all from Bayer Corp. (Pittsburgh, Pa.), SPECTRIM
reaction moldable polyurethane and polyurea systems from Dow
Chemical USA (Midland, Mich.), including SPECTRIM MM 373-A
(isocyanate) and 373-B (polyol), and ELASTOLIT SR systems from BASF
(Parsippany, N.J.). Preferred RIM systems include BAYFLEX MP-10000,
BAYFLEX MP-7500 and BAYFLEX 110-50, filled and unfilled. Further
preferred examples are polyols, polyamines and isocyanates formed
by processes for recycling polyurethanes and polyureas.
Additionally, these various systems may be modified by
incorporating a butadiene component in the diol agent.
[0083] Another preferred embodiment is a golf ball in which at
least one of the boundary layer 28 and/or the cover layer 24
comprises a fast-chemical-reaction-produced component. This
component comprises at least one material selected from the group
consisting of polyurethane, polyurea, polyurethane ionomer, epoxy,
and unsaturated polyesters, and preferably comprises polyurethane,
polyurea or a blend comprising polyurethanes and/or polymers. A
particularly preferred form of the invention is a golf ball with a
cover comprising polyurethane or a polyurethane blend.
[0084] The polyol component typically contains additives, such as
stabilizers, flow modifiers, catalysts, combustion modifiers,
blowing agents, fillers, pigments, optical brighteners, and release
agents to modify physical characteristics of the cover.
Polyurethane/polyurea constituent molecules that were derived from
recycled polyurethane can be added in the polyol component.
[0085] The surface geometry of the golf ball 20 is preferably a
conventional dimple pattern such as disclosed in U.S. Pat. No.
6,213,898 for a Golf Ball With An Aerodynamic Surface On A
Polyurethane Cover, which pertinent parts are hereby incorporated
by reference. Alternatively, the surface geometry of the golf ball
20 may have a non-dimple pattern such as disclosed in U.S. Pat. No.
6,290,615 for A Golf Ball Having Tubular Lattice Pattern, which
pertinent parts are hereby incorporated by reference.
[0086] From the foregoing it is believed that those skilled in the
pertinent art will recognize the meritorious advancement of this
invention and will readily understand that while the present
invention has been described in association with a preferred
embodiment thereof, and other embodiments illustrated in the
accompanying drawings, numerous changes, modifications and
substitutions of equivalents may be made therein without departing
from the spirit and scope of this invention which is intended to be
unlimited by the foregoing except as may appear in the following
appended claims. Therefore, the embodiments of the invention in
which an exclusive property or privilege is claimed are defined in
the following appended claims.
* * * * *